The actual Krackenator XX6 Sparks drag pipe has a 2 1/2" core and a 11" can. The one Morgan tested is a Krackenator X6 with a 2 1/4" core and a 14" can. I believe the Krackenator X6 and the Krackenator XX6 both step up in size where the header slides into the rear section. This is not intended to discredit Morgans findings, just clarifing the differences between the 2 exhausts. The exhaust Kenz tested was a Krackenator XX6.